1. Field of the Invention
The present invention relates generally to an apparatus and method for analyzing motions using bio-impedance and, more particularly, to an apparatus and method for analyzing motions using the variation of bio-impedance attributable to joint movement at a certain position on a living body.
2. Description of the Related Art
Studies on the motion analysis of humans have focused on a lower limb during a gait, which employ an observational analysis method, an image analysis method, and analysis methods using an ElectroMyoGraph (EMG), a goniometer and a force plate.
The observational analysis method is disadvantageous in that accurate data cannot be obtained because measured values should be read by the human eyes.
The image analysis method obtains data necessary for gait analysis by attaching one or more reflectors to a human body, measuring the position values of the reflectors using a plurality of infrared cameras and computing the measured position values. This analysis method is capable of obtaining relatively accurate data, but disadvantageous in that the costs required to construct a system are high and the system occupies excessive space.
The EMG using bio-signals observes the states of muscles, that is, the activities of muscles, rather than direct information on the motions of a human body, so that it is unsuitable for the accurate and continuous measurements of the variations of a joint, unlike a goniometer and an image analyzer.
The goniometer is attached to a joint and analyzes the motions of the joint, so that the method using the goniometer is the most accurate analysis method. However, the goniometer is disadvantageous in that it cannot continuously measure values and restricts the free movement of joints.
The image analysis method and the method using the force plate are disadvantageous in that the sizes of the equipment therefor is large and the utilization thereof is possible only in the place where the equipment is installed. There have been utilized pressure gauges that are fabricated in the form of shoes so as to measure the pressure distribution like the force plate. However, the pressure gauges are disadvantageous in that the sizes thereof should be made to fit the feet of examinees and they should be attached to the feet of the examinees while the examinees are walking.